THE COMPLETE GUIDE TO

Sustainable Materials Selection

Take an in-depth look at the different aspects involved when selecting sustainable materials and suppliers for your projects.


What is sustainability?

What is sustainability?

Sustainability is preserving the environment today for the generations of tomorrow to be able to live in it safely. However, sustainability goes deeper than that to incorporate three main dynamics, called the three E’s of sustainability; those are environment, equity, and economics.

Evidently, the environment is what we are making every effort to protect and maintain.

When it comes to making environmental decisions, equity is what ensures fairness is at the forefront of our considerations.

Whereas economics mainly considers the fact that in our endeavours to preserve the environment, subsistence and livelihoods are also well safeguarded.

In our modern-day world, it is quite challenging and almost unavoidable not to impact our planet’s environment in one way or another.

However, studying, understanding, and applying sustainability measures can help minimise our impact as individuals, organisations, and societies.

Furthermore, a pan-effective event as in the coronavirus pandemic putting the world through a lengthy downtime has been a wake-up call to many governments, organisations, and individuals across the world that arguably the most effective way to survive economic damages is through sustainability.

As mentioned in Global Recycling’s editorial in its second issue, the World Bank Group has stated that supporting a country’s development through sustainability-based approaches in the recovery phase from the pandemic can help build the country’s resilience and prosperity.

“There are encouraging signs from some countries – including China, Germany, and South Korea – that are looking at green elements as part of their recovery.”

World Bank Group

Sustainability in materials selection

When it comes to materials selection, sustainability has become an increasingly critical factor to consider.

In addition to a material’s properties, ease of manufacturing, cost, and other attributes relevant to its application areas, its impact on the environment has become an indispensable consideration.

Every material and end product hold an environmental footprint, characterised by their fabrication, processing, design, durability, and reusability.

Material comparison

In the context of materials, sustainability takes the form of smarter production technologies, recyclability, material longevity, biodegradability, lower CO2 emissions, and a well-established circular economy.

Whether it is through discovering new materials that are less toxic to the environment or reusing and remanufacturing existing materials and products to minimise waste, sustainable materials are now more important than ever.

In 2017 alone, the global use of material resources hit the 90 billion metric tons mark. This is expected to increase at least twofold by the year 2050.

With a shift in the extraction of materials from the conventional Asian, European, and North American regions to more local sites throughout the developing world – Africa, in particular – the living standards there are definitely on the rise.

However, all this has raised red flags from an environmental standpoint, whether it is the impacts on the climate, the land, the biodiversity of species, or the biogeochemical cycles.

As we embark on a future that could bring unprecedented dangers, it is imperative that we all contribute to mitigating our impact on the environment, especially that of materials use.

Not only is it urgent to proactively evaluate our impact, but it is also vital that we devise new interdisciplinary approaches and apply solutions that would slow down the rate at which the world is impinging on the environment.

In the following sections, we will explore the many aspects of sustainability that materials suppliers and users have been undertaking as part of their collective mission towards a more sustainable future.

Metals, plastics, composites, ceramics and glass materials

Sustainability in a circular economy

As material resources are becoming less and less abundant, waste piling up with limited disposal spaces, and CO2 emissions triggering dangerous changes in our climate, there is an exigency that we begin transitioning from the tradition linear economy scheme to a reasonably circular economy.

Circular economy vs linear economy

The difference between both economic structures lies in the waste output of industrial or commercial processes, in which a linear economy follows the progression from the input level, where raw materials are mined, to processing and product usage, followed by waste disposal in landfills at the output level.

In other words, it follows the old-fashioned sequence of “take – make – use – dispose”.

On the other hand, a circular economy is designed particularly with minimising waste in mind.

That is through reducing, reusing, recycling, and remanufacturing products and materials for further use instead of discarding them after their first use.

Such an economic scheme highlights the importance and potential of sustainability-based thinking, especially in how it helps reduce:

our dependency on diminishing resources through reusing certain materials,

our global carbon footprint by circumventing many production processes, and;

our waste that is winding up in the oceans.

A circular materials economy does not necessarily mean using materials that are biodegradable in nature, but rather materials that can be reused multiple times.

This helps reduce the input and output of materials and keep them, as much as possible, within that loop of “make – use – recycle”.

Materials that can help bring a circular economy into existence are those that can be reused without or with as little as possible additional processing.

That means reusability takes precedence over recyclability and remanufacturability, making sure that materials are reused sufficiently and effectively enough before reaching the point of recycling or remanufacturing.

As Michael F. Ashby puts it in his book Materials and Sustainable Development, “Materials in a circular economy are seen, not as a disposable commodity, but as a valued asset to be tracked and conserved for reuse.”

Such materials range from transition metals (e.g. titanium, gold, and steel) to post-transition metals (e.g. aluminium), alkali metals (e.g. lithium), and plastics (e.g. PET, PLA).

Steel is a 100% recyclable material with loss in material properties. It is labelled as a “permanent material” and an “ambassador of circular economy”.

Aluminium is a circular material that can be recycled indefinitely without losing its initial properties. It is a fundamental element of a circular material economy.

PET is a highly energy-efficient material and is, in fact, the most recycled plastic material. Upon recycling, its feedstock can be recollected and reused.

PLA is a biodegradable polymer that is produced from renewable raw materials. It is known to have one of the lowest carbon footprints of all plastic material.

In the 2019 annual report of the Bureau of International Recycling (BIR), Henk Alssema, chairman of the BIR Plastics Committee, mentioned that the plastics recycling market is undergoing a transition from the existing linear approach to the new circular models.

He also highlighted that the one of the fundamental elements in developing a circular economy is collaboration. “No single government or business is large enough to operate alone in this transition phase,” he added.

“We have to accept that old models are no longer sustainable and that the shipping of large amounts of plastic waste may cease to happen in the future.”

Henk Alssema, Vita Plastics (NDL), Chairman Plastics Committee

It is important to keep in mind that a circular economy is more than simply recycling materials efficiently. It involves using renewable energy and tracking the materials as they progress throughout the economy to enable their proper reusage with minimal reprocessing.

To ensure the latter, material efficiency is taken into consideration. Material efficiency is making more material services available while reducing material production from raw materials.

In the next section, we will discuss the impact of recyclability and what the most common recyclable materials are.

The impact of recyclability

The impact of recyclable materials

Recyclable materials are materials that can be made into new products to be reused with little to no waste. Recycling is a valuable consideration that fits well in the scheme of a circular economy, as it is intended towards minimising the input and output of a material’s life cycle.

An advantage that recycling has over reuse lies in the fact that whereas reused products are used merely within the limits of their initial system, recycled products can re-join the primary production cycle to be utilised in more ways. However, this comes at the expense of a greater loss in value.

The ability of a material to be recycled has been an increasingly important factor in material selection, especially in application areas where waste disposal has resulted in a dangerous impact on the environment.

For instance, plastics, glass, metal, paper, textiles, and organics – known as the six main categories of household waste – are all recyclable materials that, instead of getting discarded, can be remade into new products to be reused.

Moreover, the global metal recycling market is forecast to grow at a rate of 7% over the next 7 years, mainly owing to industrialisation, urbanisation, and the increased commodity consumption coupled with alarmingly depleting natural resources3.

Nowadays, the 5 most common recyclable engineering materials include:

  • 1.

    Steel

  • 2.

    Aluminium

  • 3.

    PET (polyethylene terephthalate) plastic

  • 4.

    HDPE (high-density polyethylene) plastic

  • 5.

    Glass

Steel: leading the way

Steel tube

Steel is not only a fully recyclable material but also a reusable material that can be used multiple times with little to no loss in its quality.

It is the most recycled engineering material in the world per ton. According to the Association of European Producers of Steel for Packaging (APEAL), the recycling rate of steel packaging has reached a record-high 82.5% as of 2018.

In other words, out of every ten steel products in the European market today, at least eight have been recycled into new products.

“Steel is circular by design,” said A.V. Maercke, secretary-general of APEAL. “Magnetic properties make steel easy to collect and steel can be recycled over and over again without any loss of material quality.”

A 2020 report by US-based company Reports and Data stated that ferrous materials are becoming increasingly in demand in metal recycling, showing that the 2018 recycling rates for ferrous scrap in different application areas were as follows:

    Automobiles: 106%

    Structural steel: 98%

    Appliances: 90%

    Reinforcement steel: 70%

    Steel cans: 66.8%

“A recycling increase of two percentage points sends a clear message to all stakeholders in the value chain that steel for packaging is a tried, tested and sustainable packaging solution, fit for a 21st century circular economy.”

Alexis Van Maercke, Secretary General of APEAL

Partner steel suppliers:

Deutsche Edelstahlwerke (DEW)

Manufacturer and Distributor

Deutsche Edelstahlwerke (DEW), a leading manufacturer and processor of innovative steel products, is producing the 100% recyclable Green Steel. Made using fully green electricity, Green Steel is sustainably manufactured from 90% scrap and 10% alloying elements.

Aluminium: the runner-up

Aluminium cube

Aluminium is, generally, recycled and processed in a similar manner to steel. Thanks to its corrosion resistance, aluminium can be used almost indefinitely without any noticeable loss in material quality.

This renders it an infinitely recyclable material, and as such, it is one of the most recycled materials. In the US alone, three out of every four aluminium products ever produced are still in use today.

Furthermore, recycling of aluminium can help save 95% of the energy required for primary production due to its relatively low energy consumption. Consequently, an equivalent reduction in carbon emissions can be achieved.

With around 2.5 million tonnes of end-of-life aluminium scrap recycled in Europe annually, high recycling rates have been reached in:

    Construction and automotive: 90%

    Packaging: 65%

    Beverage cans: 74.5%

According to European Aluminium, the aluminium industry has set an aim of recycling 100% of its beverage cans by 2030 and 75% of its aluminium packaging by 2025.

Partner aluminium suppliers:

Nature Alu

Manufacturer

Nature Alu is a manufacturer of high-purity aluminium with the lowest environmental footprint in the industry. Its aluminium products are 100% recyclable with an unlimited recyclability.

Gränges

Manufacturer

Gränges is a leading supplier of advanced rolled aluminium materials. Their products provide both increased business and sustainability benefits to customers, especially with their lightweight properties, high recyclability, and improved resource efficiency.

PET plastic: a strong contender

PET plastic sheet and granules

Polyethylene terephthalate is a clear, lightweight, and inert polymer that is mainly used in hygienic packaging, particularly food packaging, beverage bottles, and textile fibres.

It has an almost perfect recyclability despite the decrease in its internal viscosity upon each cycle.

It is the most recycled plastic material, especially considering that it may take a period of five centuries for PET plastic to degrade in a landfill.

Recycling helps the PET industry minimise its environmental impact through:

    Less usage of raw materials: new bottle preforms can be produced with ~35% regranulate, thus saving a relative amount of crude oil that would have been needed to generate new granulate.

    Less energy requirements: recycling of plastics uses around 12% the energy needed to produce plastics from raw materials.

According to a 2020 report by Acumen Research and Consulting (ARC), the global market for recycled PET is estimated to grow at a rate of 8% between 2019-2026, to reach a value of about US$12.5 billion.

However, recycling plastic rates are still far from where they should be, with only about 30% of plastic waste is subjected to recycling.

Sustainable PET in action

Preventing plastics from reaching the oceans
VYPET™ VNT-102 HS is a mixed-colour unfilled PET that is produced from 99% ocean bound plastics. It’s just one way that Lavergne, a supplier of high-quality resin made from recycled plastic, is doing their bit to make plastic circular. Learn more about this material.

Making electrical parts from post-consumer recycled plastic
VYPET™ VNT 615FR is a 15% fiberglass-reinforced flame-retardant PET compound that is processed with injection moulding and designed for electrical and structural applications. Its content includes post-consumer recycled (PCR) plastic while maintaining excellent mechanical properties and dimensional stability. Learn more about this material.

High-temperature performance with recycled PET compound
VYPET™ VNT 340 SK is a 40% glass/mineral-reinforced PET injection-moulding compound designed particularly for electrical applications where equal flow / cross dielectric properties are required. Used in electric motors, ignition systems, and grills, this PET compound exhibits excellent high-temperature properties, all the while having PCR content. Learn more about this material.

Partner PET suppliers:

Lavergne

Manufacturer

Lavergne is a manufacturer of high-quality recycled resins that can be upcycled into new products. They use 100% post-consumer recycled (PCR) plastics to design, develop, and produce high-value sustainable resins (alloys and composites).

HDPE plastic: another sturdy challenger

HDPE granules

High-density polyethylene is a thermoplastic that has a relatively high specific strength and heat resistance. It is used for pipes, toys, chairs, fuel tanks, bottles and other hard packaging containers.

A recent study on the LCA of recycling postconsumer HDPE and PET found out that recycling HDPE offers significant environmental benefits as compared to single-use virgin HDPE materials, including 87% reduction in energy and 64% reduction in carbon emissions.

According to the “Global Plastic Recycling Industry” report (2020) by Global Industry Analysts (GIA), the HDPE market segment is set to grow at a rate of 6.8% to reach US$13.7 billion by 2027.

Partner HDPE suppliers:

Green World Compounding

Manufacturer

Green World Compounding is a producer of recycled plastic pellets and shreds, with over 30m kilograms of plastic recycled every year. Its product range includes HDPE, LDPE, PP, and composites of PP reinforced with recycled fiberglass.

Glass: the good old rival

Circular glass

Glass is one of the oldest engineering materials ever produced and still is a highly valuable commodity. It is also very easily recycled since it is basically made of sand.

However, glass is still being dumped in landfills despite the fact that it does not decompose – not in a million years at least.

According to the United States Environmental Protection Agency (EPA), in 2017, out of the 139.6 million tonnes of municipal solid wastes landfilled in the US, 4.9% were glass. That amounts for about 7 million tonnes of glass in landfills. In comparison, about 2.7 million tonnes of glass were recycled in the same year.

This shows the urgent need – and simultaneously, a window of opportunity – to improve glass recycling. According to a market forecast by Inkwood Research, the global recycled glass market is estimated to grow at a CAGR of 6.19% in volume between 2020 and 2028.

Partner glass suppliers:

SCHOTT AG - Glass Tubing

Manufacturer and Distributor

SCHOTT is a leading global technology group specialised in producing specialty glass and glass-ceramics. With their range of high-quality products, SCHOTT assumes special responsibility for the environment.

But that’s not all...

In addition to those five common materials, many other materials are either partially recyclable or show recyclability potential.

One example is Pebax® C 63C73 SP 01 resin from Arkema, a thermoplastic elastomer made of flexible polyether and rigid polyamide from renewable resources. It is a heat- and UV-resistant grade that is used in footwear. It is shown to have 51% renewable carbon content.

Despite being extremely important, recyclability is not the only key aspect of sustainability. Next, we shift our focus to biodegradable materials.

Are biodegradable materials sustainable?

Biodegradable materials

Biodegradability represents a material’s ability to decompose upon its interactions with biological elements.

It may disintegrate completely or partially, depending on its level of biodegradability, the microorganisms contacting it, and its environmental conditions.

A biodegradable polymer material, for instance, that comes from renewable resources is generally classified as a green polymer, as it is characterised as an alternative to materials derived from petrochemical resources.

Since biodegradable polymers can naturally be composted with microorganisms and enrich soils, they hold a significant advantage in degradation over other polymers.

This helps stabilise the environment, extend the lifespan of landfills, and consequently, reduce the labour cost of removing nonbiodegradable traditional plastics from polluted areas.

Furthermore, biodegradable polymers can be reprocessed by certain treatments that involve microbes, enzymes, or hydrolysis, to make oligomers that are useful for different applications.

Biodegradability of materials is determined by biodegradability tests, which measure the complex biochemical processes taking place when microorganisms consume the given material. The ability of a product to degrade relies mainly on how much carbon is present for microbes to consume it.

Claims of biodegradability are required by regulations today to be based on aerobic biodegradation. This refers to the disintegration of the organic material in the presence of oxygen, and it measures the consumption of oxygen, the production of carbon dioxide, and the state of inorganic carbon intermediates.

Two main biodegradable polymers that have started gaining commercial traction are PLA (polylactide) and PHA (polyhydroxybutyrate). They are cost-competitive materials and have begun replacing a few of their nonbiodegradable counterparts, especially PLA in food packaging applications.

However, there is still a lot of research required to develop blends of biodegradable polymers that can have adequate properties and usability to replace the majority of current nonbiodegradable polymers. Basically, such materials play a significant role in areas where there is no infrastructure for recycling or recyclable materials are not much of an option, but they are not considered a circular solution.

The table below shows a variety of biopolymers and biodegradable polyester materials that are provided by Matmatch suppliers, which are used, for the most part, in packaging or 3D printing applications.

A list of biobased materials from Matmatch suppliers

SupplierMaterialDescription
Total Corbion PLAPLA Luminy® LX530It is a medium flow, fibre-grade resin with a 100% biobased content. It is both biobased and biodegradable.
Feconix Pte LtdNuPlastiQ® BC 27240It is a biodegradable biopolymer designed for film and bag applications that require biodegradation and are intended for compost environments.
Extrudrextrudr Wood FilamentIt is a biodegradable material that contains wood fibres, PLA, copolyester and additives. It imitates wood in its smell and aesthetic.
Extrudrextrudr Flax FilamentIt is made from a renewable biodegradable biopolymer developed for use in rapid prototyping and design.

It is important to note that biodegradation does not indicate biobased content. Rather, it is based on the material’s molecular structure that allow it to disintegrate upon contact with microorganisms under the right environmental conditions.

In the case of PLA and PHA, since they are derived from renewable plant materials and are biodegradable to be converted back to carbon dioxide that is collected by plants via photosynthesis, the production of these aliphatic polyesters is regarded as ‘carbon neutral’. In other words, the net carbon amount in the environment stays constant in the long term.

So, to answer the main question, biodegradable materials can be considered sustainable to a certain degree, taking into consideration the sustainability of their raw materials.

In the following section, we will explore the carbon footprint and embodied energy of engineering materials and the process of minimising them.

Partner suppliers of biodegradable materials:

Total Corbion PLA

Manufacturer

Total Corbion PLA is a global technology leader in polylactic acid (PLA) and lactide monomers. It produces 75,000 tons of PLA annually, with 100% biobased content and 100% biobased carbon content according to EN16785-1.

Feconix Pte Ltd

Distributor

Feconix is a start-up that provides green and eco-friendly solutions to fight climate change and environmental pollution. Of their product range is the NuPlastiQ® BC family, which is biodegradable even when blended with other resins.

Extrudr

Manufacturer and Distributor

Extrudr is a specialised producer of technical monofilaments used for additive manufacturing. These include biodegradable materials and biopolymers that provide high-quality performance while maintaining their sustainability features.

Minimising materials’ carbon footprint and embodied energy

Carbon footprint of material production

It is commonly known that one of the most significant sources of greenhouse gas emissions today is materials production.

Between 1995 and 2015, a 120% increase in CO2 emissions from material production has been observed to account for 23% of global emissions, two fifth of which are used in manufacturing machinery, vehicles, and other products. Correspondingly, policies and processes today are aimed at augmenting the efficiency of materials and transitioning to a circular economy.

One of the most acknowledged and commonly used techniques to evaluate a material’s environmental impact is the Life Cycle Assessment (LCA). It is a cradle-to-grave analysis method that determines the environmental burdens relative to every stage of a product’s life cycle, from the extraction of raw materials through processing and manufacture all the way to its distribution, use, and disposal.

Throughout this life cycle, it is critical that the carbon emissions at every stage are monitored, assessed, and minimised to the lowest levels possible. However, LCA being a scrupulous quantitative assessment requires a lot of time and skill to be well implemented.

With that in mind, scientists and engineers look at simpler and faster approaches to evaluate a material’s impact on the environment. They strongly recommend the selection of materials with lower environmental burdens in the initial stages of a product’s development. And in order to understand and evaluate those burdens, they utilise two main indicators in their materials selection: embodied energy and carbon footprint.

Embodied energy is the total amount of energy associated with the extraction, processing, production, and delivery of a material or product. It does not cover the operation and disposal of the material but rather the ‘upstream’ sections of an LCA. This concept helps simplify the evaluation of a product’s environmental impact.

The figure below shows the different energy values typically required to produce different engineering materials.

Graph showing embodied energy per unit mass of different materials

Embodied energies of engineering materials. (Materials and Sustainable Development, © 2015 Michael Ashby)

Minimising the embodied energy of a product is crucial in reducing its environmental impact.

For example, in an LCA mentioned in the book “Use of Recycled Plastics in Eco-efficient Concrete”, it was shown that producing polypropylene (PP) with a 70% recycle fraction can reduce the embodied energy by two thirds from that of virgin PP, to about 25 MJ/kg.

Similarly, producing aluminium that is only 30% recycled can results by a reduction of at least 50 MJ/kg from the embodied energy of primary aluminium (~ 215 MJ/kg).

On the other hand, a material’s carbon footprint is the total amount of greenhouse gas emissions generated through the material’s lifecycle.

It can also be defined as the amount of biocapacity demand to close off the CO2 emissions from the combustion of fossil fuels taking place due to the production of the material or product.

As described in BIR’s 2019 Annual Report, for example, recycling has helped save a significant amount of CO2 emissions for many recyclable materials, as shown in the table below.

The minimum carbon emission savings for different materials upon recycling.

Recycled MaterialMinimum CO2 emission savings (2019)
Recycled Material92%
Copper65%
Iron58%
Paper18%
Nickel90%
Zinc76%
Copper99%
Tin99%

A 2020 action plan report by European Aluminium estimates that the volume of aluminium available for recycling will reach more than two times the current amount by 2050.

It states that “With a well implemented policy framework, increased recycling of aluminium could avoid up to 39 million tonnes of CO2 emissions per year by 2050.”

Clearly, recycling aluminium offers a substantial possibility to reduce greenhouse gases via replacing primary aluminium with a gate-to-gate-based aluminium.

The figure below shows the difference in greenhouse gas emissions between primary aluminium and recycled aluminium based on European Aluminium’s estimates.

Graph showing CO2 emissions of aluminium production

Greenhouse gas emissions of primary aluminium production and recycling process [European Aluminium]

Furthermore, if “high recycling” scenarios are applied, in which a high proportion of post-consumer recycled aluminium is considered, estimates show that around 46% of the annual carbon emissions can be reduced by mid-century.

Aluminium is only one example of materials that provide opportunities to minimise their carbon emissions and sustain a more circular economy.

In a 2019 peer reviewed life cycle impact assessment of PLA, researchers found out that the global warming potential (GWP) of PLA is merely 501 kg CO2 eq/ton PLA.

That is a reduction in carbon footprint of about 75% versus most traditional fossil-based plastics, as PLA producer Total Corbion states.

“As a matter of urgency, politicians and policy-makers need to understand this message about the huge carbon dioxide emission savings achieved through using recycled materials.”

Olivier Francois, Chairman International Environment Council

Partner suppliers of low-carbon-footprint materials:

Deutsche Edelstahlwerke (DEW)

Manufacturer and Distributor

Deutsche Edelstahlwerke (DEW), a leading manufacturer and processor of innovative steel products, is producing the 100% recyclable Green Steel. Made using fully green electricity, Green Steel is sustainably manufactured from 90% scrap and 10% alloying elements.

Total Corbion PLA

Manufacturer

Total Corbion PLA is a global technology leader in polylactic acid (PLA) and lactide monomers. It produces 75,000 tons of PLA annually, with 100% biobased content and 100% biobased carbon content according to EN16785-1.

RUSAL

Manufacturer

RUSAL is the largest aluminium producer of low-carbon aluminium (ALLOW™) made with renewable hydropower. Over the last decade, it has recycled on average over 50% of waste generated at its aluminium smelters.

Nature Alu

Manufacturer

Nature Alu is a manufacturer of high-purity aluminium with the lowest environmental footprint in the industry. Its aluminium products are 100% recyclable with an unlimited recyclability.

Gränges

Manufacturer

Gränges is a leading supplier of advanced rolled aluminium materials. Their products provide both increased business and sustainability benefits to customers, especially with their lightweight properties, high recyclability, and improved resource efficiency.

Stora Enso Biocomposites

Manufacturer

Stora Enso is a leading global provider of renewable solutions in packaging, biomaterials, wooden constructions, and paper. In 2019, their products saved an estimated 20 million tonnes of CO2, and their total climate benefit was 12 million tonnes of CO2.

How to source sustainable materials

Sourcing sustainable materials

Here at Matmatch, we believe it is essential that a materials selection platform incorporates the aspect of environmental impact in the strategies of material selection and decision making for engineers.

That is why we have incorporated this sustainability section.

We want to help engineers and product developers make more informed decisions about preserving the environment while conducting their projects.

If you need help finding sustainable materials or have any feedback, get in touch with us below.

If you are a materials supplier that wants to promote your sustainable material solutions, we’d be happy to show you how we can help.

Get in touch

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